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CentrePoint Study Admin Update 1.6.0

When will this change take place?

The changes described below will take effect beginning with version 1.6 (on or around August 6, 2014).

Overview

ActiGraph is making some changes to the data exports available in CentrePoint (Custom Exports are unaffected). The following table summarizes the changes.

Subject Data Level

Export Name (location)

Column Changes

Notes

Minute Summary (Epoch)

Export CSV → Epoch

(Subject Details,

Study Dashboard,

Study Details pages)

-- & --

Details → Export CSV

(Subjects listing page)

Added:

AxisXCounts

AxisYCounts

AxisZCounts

Removed:

DownProjectedCounts

These are 60 second totals

Daily Summary

Day Stats

(Subject Details page)

-- & --

Study Day Stats

(Study Dashboard)

Added:

AxisXCounts

AxisYCounts

AxisZCounts

WearFilteredAxisXCounts

WearFilteredAxisYCounts

WearFilteredAxisZCounts

These are daily totals

Overall for Study

Subject Stats

(Study Dashboard, Study Details pages)

Added:

AxisXAverageDailyCounts

AxisYAverageDailyCounts

AxisZAverageDailyCounts

WearFilteredAxisXAverageDailyCounts

WearFilteredAxisYAverageDailyCounts

WearFilteredAxisZAverageDailyCounts

What data changes occurred (or will occur) in the 1.6 release?

Removal of the variable DownProjectedCounts from all areas in CentrePoint (this excludes custom exports).

Changes to Web Portal Charts and Reports (there are also screen images below to illustrate the following changes)

Subject Details page: The “Activity Counts Per Day” chart and the “AVG Daily Counts” value both previously represented DownProjectedCounts and now they both represent Axis Y Counts.

Subject Daily Details page: (1) "AVG Daily Counts" previously represented an average of DownProjectedCounts and will now represent Axis Y Average Daily Counts (2) For the Daily Activity table, the "Counts" column has been removed and the columns Axis X Counts, Axis Y Counts and Axis Z Counts have been added.

Subject Minute Summary page: (1) The “Steps Per Minute” chart has been replaced with an "Axis Y Counts per Minute" chart. (2) For the Minute Activity table, the "Counts" column has been removed and the columns Axis X Counts, Axis Y Counts and Axis Z Counts have been added.

Changes to CSV Exports

Custom exports are not changed.

Subject Minute Summary “Epoch” export

Added columns

Axis X Counts

Axis Y Counts

Axis Z Counts

Removed columns

DownProjectCounts.

Subject Daily Summary “Day Stats” and “Study Day Stats” export

Added columns

AxisXCounts

AxisYCounts

AxisZCounts

WearFilteredAxisXCounts

WearFilteredAxisYCounts

WearFilteredAxisZCounts

Subject Overall “Subject Stats” export:

Added columns

AxisXAverageDailyCounts,

AxisYAverageDailyCounts

AxisZAverageDailyCounts

WearFilteredAxisXAverageDailyCounts

WearFilteredAxisYAverageDailyCounts

WearFilteredAxisZAverageDailyCounts

Changes to API

Subject Minute Summary “dayminutes” and “sleepepochs” endpoints:

Added columns

AxisXCounts

AxisYCounts

AxisZCounts

Deprecated columns

X

Y

Z

Removed columns

DownProjectedCounts

DownX

DownY

DownZ

Subject Daily Summary “daystats” endpoint:

Added columns

AxisXCounts

AxisYCounts

AxisZCounts

WearFilteredAxisXCounts

WearFilteredAxisYCounts

WearFilteredAxisZCounts

Subject Overall “stats” endpoint:

Added columns

AxisXAverageDailyCounts,

AxisYAverageDailyCounts

AxisZAverageDailyCounts

WearFilteredAxisXAverageDailyCounts

WearFilteredAxisYAverageDailyCounts

WearFilteredAxisZAverageDailyCounts

Removed columns

AverageDailyCounts

AverageDailyWearFilteredCounts

The images shown below summarize these changes; click each image for a larger view:

What are DownProjectedCounts?

To understand DownProjectedCounts, one must first understand counts (see What are Counts?). Counts are usually used to describe the magnitude of activity levels in the X, Y and Z axes of an activity monitor. The DownProjectedCounts value was developed by ActiGraph engineers as a way to eliminate the need for proper device orientation in order to accurately measure "overall" counts. DownProjectedCounts are essentially a vector summation of acceleration in all three axes "down projected" onto the gravity vector. The idea with this value is that it should accurately represent activity counts directly against gravity regardless of the orientation of the device.

Why are they being removed from CentrePoint?

There are no publicly available algorithms or activity monitor interpretations of DownProjectedCounts. ActiGraph engineers developed the term in order to attempt to more accurately represent orientation-independent actigraphy.

What is impacted?

The section entitled What data changes occurred (or will occur) in the 1.6 release? outlines the exports and user interface changes that were impacted. The CentrePoint API was also impacted.